Yellowhammers can be found across the whole Palearctic region reaching its southernmost limit in northern Spain and the Mediterranean. It formerly bred across the Bailiwick but is now extinct as a breeding species on all the islands. The last confirmed breeding record in Guernsey was in 1983 and the last record of birds occurring at a suitable site during the breeding season occurred in 1987.

Yellowhammers have only ever had a tentative foothold in the Bailiwick but have bred in small numbers in Alderney, Guernsey and Sark. In Guernsey, Smith describes the species as not common in 1878 and it was considered very rare in 1919 but much commoner the next year (Dobson). During a series of short visits to Guernsey in 1946, Dobson failed to find any Yellowhammers but concedes that he wasn't looking in the most likely places above the south cliffs. A pair was proved to breed in 1949 with the nest located in thick gorse, which is typical of Channel Island nests, but there is little published information since. [CHECK OLD TRANS].

In Alderney, Smith considered Yellowhammers to be breeding and slightly more common than in Guernsey and Eagle Clarke found the bird common in September 1898. Between 1912 and 1934 there are conflicting reports as to the bird's status. Thompson never saw any birds, yet Langlois frequently found birds nesting. The situation in Sark seems similar to Guernsey and, since the first record in March 1898, there have been irregular records since with the last confirmed breeding in 1970 (Rountree 1972). It seems as though it was a rare and irregular breeder throughout the Bailiwick.

Since 1945, the number of birds breeding in the Bailiwick has probably always been in single figures although old accounts in the Transactions are vague and call the Yellowhammer a 'not common resident and migrant' in Guernsey (1961 Transactions). Conder mentions that single birds were recorded in Alderney in many years from 1953-1976 and that they might have bred. In Sark, Rountree lists one confirmed and one probable breeding record in 1970 and also a further 17 records from 1966-72. In his supplement, he lists three further records to from 1973 to May 1991.

Since the start of the GBN in 1969, the documentation of Yellowhammers improved and detailed the final extinction of Yellowhammers in Guernsey. The majority of breeding pairs were along the south coast of the island and pairs tended to be associated with cereal crops. In winter, birds spread out around the island and were often seen in coastal areas all around Guernsey. Unfortunately most records received during the breeding season were not confirmed breeding records and so the decline in this species has had to be deduced.

During the 1970s, small numbers of birds were seen during the breeding season along the south coast of Guernsey and graph showing number of possible breeding pairs shows that the number of breeding birds varied from a maximum of 8 birds in 1970 to c.2-4 pairs in the middle of the decade to 5-7 pairs at the end. Birds held territories at many sites along the south coast cliffs but regular sites included Les Sommeileuses, Le Gouffre, St Martin's Point, Saint's Bay, Corbière, and Pleinmont. Most records were of singles or pairs of birds but finding 2 singing males at a site was not unusual, although 7 singing birds at Corbière in May 1970 certainly was (GBN). Birds were not restricted to coastal sites and males regularly held territories at Fauxquets Valley and at the Silbe Nature Reserve in the Quanteraine Valley during this period.

After a slight increase to c. 5 pairs at the end of the 1970s, there was a slow but steady decline in the number of possible breeding records during the 1980s. In 1980, four sites were occupied - Fauxquets, Silbe, Les Sommeileuses and Le Gouffre. Numbers never reached above four again and fluctuated between 3-4 occupied sites until 1986 when birds were only present at two, Les Sommeilleuses and the Vaux de Monel. The following year 2 males and a female were present at Pleinmont on 22 May but no evidence of breeding was obtained. In the Guernsey Bird Report for that year, Bourgaize and Watson write 'Guernsey appears to have lost its very few resident birds and has to rely on sightings of migrants for records.' This was the last year in which there was an unbroken run of Yellohammer records during the breeding season. None were recorded in 1988 and Yellowhammers are now a rare (mostly spring) migrant and winter visitor.

Although it is not possible to be sure exactly sure when the Yellowhammer became extinct as a breeding species in Guernsey, the last confirmed breeding record comes from Le Fond du Val. A bird was seen there carrying food on 10 May 1983. Males were regularly seen holding territories at four sites the following year but no proof of breeding was obtained then or since.

The extinction of the Yellowhammer as a breeding species is undoubtedly a result of changes in agricultural practice. Throughout the 19th century, the loss of traditional mixed Guernsey farming and the increase in intensively managed dairy farms led to a large reduction in the area of cereal crops grown on the island and also the availability of cereal stubbles in the winter. Greater use of pesticides and fertiliser also reduced the availability of hay fields and or stubbles which had high densities of cereal or weed seeds which are important for over-winter survival.